The secret to razor sharp serrations is SANDPAPER!

[Dan4governor]

Hey guys, I just wanted to share a quick hack I came up with. I LOVE serrated and combo edge knives, but I always got so freaking frustrated trying to sharpen them. Until I figured out that the secret isn’t a special tool, it’s just sandpaper wrapped around a round tool (like a screwdriver) then finish with a piece of denim with metal polish (wrapped around the same tool). I’m so stoked about this find that I made a quick video of it if you want to see the exact technique. SUPER EASY and with basic household items. Let me know what you think! And also let me know if you have something that works better!

also, if you don’t want to watch the video, I can post screen shots with the steps explained, just let me know!

 

[115Italian]

Don’t forget to strop the back side too.

 

[Twindog]

Thanks for the cool video. That's the approach I like to take (sharpening each serration individually), but it can be a pain. What we need are a set of tools in the proper diameter and in a progression of grits that match the profile of each serration.

When I sharpen my chainsaw, I have a file that exactly fits the scallop of each cutter tooth. While there's no progression of grits -- and none needed for a chainsaw -- the perfect fit of the file makes sharpening the cutters easy.

The problem I've had with wrapping sandpaper around a rod is that the diameter of the rod is changed and the technique wastes a lot of sandpaper. It's difficult to get the exact right fit, which weakens the technique. So there are a lot of factors to be aware of.

But generally, I avoid serrations -- other than the bread knife that I use to cut insulation -- because a plain edge, properly sharp, is better in almost all situations. And when the plain edge isn't, it's not far enough off to warrant a change in edges.

 

[Obsessed with Edges]

It's nice to see there are many creative ways to handle serrated edges, and it's always a good thing to add that knowledge to one's toolbox.

But I'm also convinced I don't need serrations on my knives anymore, even for things like bread. In any situation where I've originally favored them, I've since figured out I can do even better with a thinner plain-edged blade that's completely & cleanly sharpened to an acute, crisp apex. In situations where a thin blade might not be at hand, I've found that even a relatively thick blade with a polished, shallow convex, applied to minimize drag or binding behind a plain edge, is a viciously-slick, cardboard-eating beast. And a thin hollow-ground blade, with an edge finished to < 30° inclusive and something like 320-400 grit, is great for food items like bread and tomatoes. With bread especially, a smart choice of finishing grit, enough to leave some very noticeable bite in the edge, is what makes the difference and levels the performance against something like a serrated bread knife.

I have several serrated/combo-edge blades, including the same Endura4 combo-edge seen in the vid, that I've tinkered with for years in finding ways to make the serrations perform well, for serrated edges. Part of that experimentation included use of techniques similar to those shown, with various rods, sandpaper & such. But I still generally don't use or carry those knives anymore, as I'm always happier with a thinner & sharper plain-edged blade, which is also easier to sharpen up when it needs it.

 

[Dan4governor]

I agree with both of you guys that a “sharp” plain edge beats a serrated edge pretty much every time. At the end of the video when I’m cutting the cardboard I mention why I love serrated edges, just for keeping the “hard miles” off my plain edge. When I have a lot of hard cutting tasks like cardboard, rope, etc, I’d prefer to saw thru it with a serrated edge and save my plain edge for more delicate cutting tasks. Having a serrated edge means I don’t have to sharpen my plain edge as often. I’m just so happy I finally found a method that works!

 

[bgentry]

I disagree with all of the "no need for serrated knives" talk in this thread. Serrated knives have several advantages over straight blades:

A. The whole edge has points. So when you do a pressure cut into something, those points start the cut FAR more effectively than a straight edge. Try opening a plastic blister pack with a plain edge and NOT using the tip to pierce. Just do a pressure cut. Now try the same thing with a serrated blade. Serrated is much easier.
B. Because the sharp scallops are recessed from the points, they are protected from high stress. Saw a plain edge into something that's hard to cut. Now test that plain edge and see how much sharpness it has lost. Try the same thing with a serrated blade. Serrated wins BIG TIME in this case.

I still carry plain edged blades most of the time. But I really like serrated for some tasks. They stay usably sharp far longer than a plain edge, particularly when doing high pressure or moderately abusive cuts.

Brian.

 

[Dan4governor]

I disagree with all of the "no need for serrated knives" talk in this thread. Serrated knives have several advantages over straight blades:

A. The whole edge has points. So when you do a pressure cut into something, those points start the cut FAR more effectively than a straight edge. Try opening a plastic blister pack with a plain edge and NOT using the tip to pierce. Just do a pressure cut. Now try the same thing with a serrated blade. Serrated is much easier.
B. Because the sharp scallops are recessed from the points, they are protected from high stress. Saw a plain edge into something that's hard to cut. Now test that plain edge and see how much sharpness it has lost. Try the same thing with a serrated blade. Serrated wins BIG TIME in this case.

I still carry plain edged blades most of the time. But I really like serrated for some tasks. They stay usably sharp far longer than a plain edge, particularly when doing high pressure or moderately abusive cuts.

Brian.

Couldn’t agree more! That’s my exact point about keeping the heavy miles off my plain edge. A serrated edge will make quick work of a difficult cutting task (such as the security plastic you mentioned) and when I’m done I’ll still have a razor sharp plain edge ready for the next cutting task (where it would’ve normally been dulled from the previous task). Thanks for the input Brian!

 

[HeavyHanded]

Personally I've had mixed results using wet/dry for serrations - namely the fit and how tight the sandpaper are tend to undermine this for use across a lot of patterns.

For some applications, the serrated edge is absolutely worth the pain to maintain them. Picked up a Mora rope knife a while back and rehandled it, after a lot of tinkering went to resharpen it and the also recut every serration after sharpening the underlying bevel (is very much like a stainless Mora with serrations cut after the fact). Beacause of the way its set up, sharpening the bevels erodes the depth of the serrations.

The thing is a beast. I actually stopped using it and will probably give to a biddy as a present - for most people that knife will stay functionally sharp forever.

 

[Dan4governor]

Personally I've had mixed results using wet/dry for serrations - namely the fit and how tight the sandpaper are tend to undermine this for use across a lot of patterns.

For some applications, the serrated edge is absolutely worth the pain to maintain them. Picked up a Mora rope knife a while back and rehandled it, after a lot of tinkering went to resharpen it and the also recut every serration after sharpening the underlying bevel (is very much like a stainless Mora with serrations cut after the fact). Beacause of the way its set up, sharpening the bevels erodes the depth of the serrations.

The thing is a beast. I actually stopped using it and will probably give to a biddy as a present - for most people that knife will stay functionally sharp forever.

Nice work! That turned out great!